1. Field of the Invention
The present invention relates to a lens barrel and an imaging apparatus including a cam follower and a cam groove that engage with each other so that a holding frame and a cam ring move relative to each other in the optical axis direction.
2. Description of the Related Art
Digital video camcorders, digital still cameras, and other imaging apparatus form a subject image through an imaging lens and capture the subject image with a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or any other imaging device disposed downstream of the imaging lens. Some of the imaging apparatus are small and thin when they are not in operation by employing a collapsible lens barrel in which rotating a cam ring causes a movable frame to move in the optical axis direction of the imaging lens.
As a known collapsible lens barrel, there is a lens barrel which includes a cam ring having a cam groove formed in a circumferential surface thereof and a movable frame having a cam follower that engages with the cam groove and in which relative rotation between the cam ring and the movable frame around the optical axis causes relative movement between the cam ring and the movable frame in the optical axis direction. There is also a technology for achieving further reduction in size and thickness of a lens barrel and an imaging apparatus in their collapsed states by forming a cam groove with its cam groove surface shifted and a cam follower that engages with the cam groove so that the length of a cam ring in the optical axis direction is reduced.